Plug connector for a printed circuit board

ABSTRACT

An electrical plug connector for a printed circuit board which has electric circuits and edge connection pads on both sides of the board includes an insulating moulding 10 having a spine portion 11 and a conjoining plug portion 12, and electrical contact fingers 21 which are secured in through-holes 14 in the spine portion, have hooked plug ends 25 which engage in slots 18, 19 formed in the free end of the plug portion, lie in shallow slots 17 on the plug portion, and have at the other side of the spine portion free ends 30 set to resiliently engage with and be soldered to edge connection pads on a printed circuit board. The spine portion has end extensions which carry clamping bands 13 for enabling the connector to be firmly secured to the edge portion of a printed circuit board. The plug part of the moulding and the associated hooked plug ends of the contact fingers 21 are intended to simulate the edge of a two-sided printed circuit board to which the connector is to be connected, so that a conventional socket connector can be used therewith.

United States Patent 1191 Clewes PLUG CONNECTOR FOR A PRINTED CIRCUITBOARD [75] Inventor: Antony Brasher Clewes,

Nottingham, England [73] Assignee: TRW Inc., Cleveland, Ohio [22] Filed:July 11, 1973 [21] Appl. No: 378,101

[30] Foreign Application Priority Data July 14, 1972 United Kingdom33007/72 [52] US. Cl... 339/156 R; 339/17 LC; 339/176 MP; 339/217 S [51]Int. Cl. I'I05k 1/07 [58] Field of Search 339/17 F, 17 L, 17 LC, 339/17LM,15O B, 151 B, 176 MP, 176 MP, 217 S, 156

[56] References Cited UNITED STATES PATENTS 2,699,534 1/1955 Klostermann339/176 MP 3,020,510 2/1962 Kuch t 339/17 LC 3,069,652 12/1962 Greco339/176 MP 3,299,392 1/1967 Evans 339/17 L 3,404,367 10/1968 Henschen339/217 5 3,568,136 3/1971 Wells 339/156 R 3,609,633 9/1971 Hargett H339/17 L 3.656,!83 4/1972 Walterscheid H 339/176 MP X 3,757,277 9/1973Yamanoue et a1. 339/217 S X 1 July 15, 1975 FOREIGN PATENTS ORAPPLICATIONS 1,015,124 12/1965 United Kingdom 339/17 L PrimaryE.raminerRoy D. Frazier Assistant Examiner-Lawrence J. Staab Attorney,Agent, or Firm-Lawrence S. Cohen, Esq.

[5 7] ABSTRACT An electrical plug connector for a printed circuit boardwhich has electric circuits and edge connection pads on both sides ofthe board includes an insulating moulding 10 having a spine portion 11and a conjoining plug portion 12, and electrical contact fingers 21which are secured in through-holes 14 in the spine portion, have hookedplug ends 25 which engage in slots l8, l9 fomied in the free end of theplug portion, lie in shallow slots 17 on the plug portion, and have atthe other side of the spine portion free ends 30 set to resilientlyengage with and be soldered to edge con nection pads on a printedcircuit board. The spine portion has end extensions which carry clampingbands 13 for enabling the connector to be firmly secured to the edgeportion of a printed circuit board. The plug part of the moulding andthe associated hooked plug ends of the contact fingers 21 are intendedto simulate the edge of a two-sided printed circuit board to which theconnector is to be connected, so that a conventional socket connectorcan be used therewith.

8 Claims, 7 Drawing Figures PLUG CONNECTOR FOR A PRINTED CIRCUIT BOARDThis invention relates to an electrical plug connector for a printedcircuit board.

Some present day printed circuit boards are of considerable size, andhence of considerable value. Circuits carried on such a board makeconnection with external circuitry by means of plug and socketconnection means. Some printed circuit boards have circuits which endadjacent an edge of the board in connection pads with which externalcircuit connection is made by means of socket devices which matedirectly with the edge of the board, and which have resilient contactswhich make contact with the aforesaid connection pads. These connectionpads can be damaged by repeated application and removal of such socketdevices. so that ultimately a board can no longer be used simply becauseof the inability to make good electrical connection with the damagedconnection pads.

According to the present invention an electrical plug connector for aprinted circuit board which has electric circuits and associated edgeconnection pads on both sides of the board comprises an electricalinsulating moulding having a spine portion for disposition adjacent anedge of such a printed circuit board, and a plug portion extending fromthe spine portion on one side thereof for disposition remotely from suchan edge of a printed circuit board, and ha lng a transverse thicknesssubstantially equal to that of the edge of the printed circuit board,

the spine portion having a greater transverse thickness than the plugportion, and two transversely spaced rows of through-holes, which rowsof holes open adjacent the plug portion on opposite sides respectivelyof the plug portion, the holes in each row being spaced apart along thelength of the moulding, and

the plug portion having at its free end two transversely spaced rows ofslots, the slots in each row being positioned along the length of themoulding in alignment with the respective through-holes which open onthe same side of the plug portion, and

a plurality of resilient strip, electrical contact fingers eachcomprising a median fastening part, a hooked plug end part extendingfrom the median part at one end thereof. and a printed circuit boardcontacting free end part extending from the median part at the oppositeend thereof,

each contact finger having its median part extending through and fixedin one of the said through-holes in the moulding, its hooked plug endpart engaged in an associated one of the said slots at the free end ofthe plug portion of the moulding, and its free end part extending fromthe spine portion of the moulding whereby to make elecrical connectionwith an edge connection pad of a printed circuit board when theconnector is presented to an ,edge part thereof,

the said plug portion of the moulding and the contact fingers togethersimulating the edge of such a printed circuit board.

Preferably, the plug portion has a plurality of parallel shallow groovesin each of its longitudinal faces, and the plug end parts of the contactfingers lie in those grooves; and the plug portion of the moulding has alongitudinal rib at its free end, which rib lies between the two rows ofslots and projects beyond the extremities of the hooked plug end partsof the contact fingers.

According to another preferred feature of the present invention thespine portion of the moulding has first abutment means formed in outerparts thereof which define the respective outer boundaries of therespective through-holes, and each contact finger is shaped so that itsmedian part bears resiliently against the said outer part of thethrough-hole in which it is located and has second abutment meansthereon arranged to engage with the aforesaid first abutment means inthe throughhole whereby to locate and secure the contact finger in thathole.

Preferably, each through-hole in the spine portion of the moulding has aT-shaped transverse cross section having a broad part in which iscarried the associated strip contact finger, and a narrow part extendinginwardly from the broad part towards a central part of the spineportion; and each slot in the free end of the plug portion of themoulding extends from the said free end towards the spine portion, andhas a T-shaped transverse cross-section having a broad part in which thehooked plug end of the associated contact finger is inserted, and anarrow part extending outwardly from the broad part towards the contactfinger.

The spine portion may have longitudinal end extensions which extendbeyond the ends of the plug portion, and clamping means carried on eachsaid end extension which enable the connector to be secured in positonon an edge part ofa printed circuit board after positioning thereon withthe said free end parts of the contact fingers resting in electricalcontact with adjacent edge connection pads formed on the board.

One edge connector according to the present inven tion for a printedcircuit board having electric circuits and edge connection pads on bothsides thereof will now be described by way of example and with referenceto the accompanying drawings, drawn to an enlarged scale, in which:

FIG. 1 shows a front view of the connector;

FIG. 2 shows a plan view of the connector;

FIG. 3 shows a vertical section taken on the line lll- III of FIG. 1;

FIGS. 4, 5 and 6 show respectively front, plan and underside views of amoulding incorporated in the connector', and

FIG. 7 shows a vertical section taken on the line VII- -VII of FIG. 4.

Referring now to the drawings, the connector comprises anelectrically-insulating moulding 10 of a thermoplastic mouldingmaterial, such as polycarbonate material, and having a spine portion 11and a conjoining plug portion 12. Lengthwise the spine portion extendsbeyond the plug portion and carries at its ends clamping bands 13 forsecuring the connector firmly to an edge part of a printed circuitboard, as will be explained later.

Whereas the plug portion has a transverse thickness which corresponds tothe thickness of a printed circuit board to which the connector is to besecured, the spine portion has a greater thickness and projects on bothsides of the plug portion. The spine portion has formed therein twolongitudinally-extending rows of spaced parallel holes 14 of T-shapedcross-section,

which holes open on to the respective longitudinal faces l5, 16 of theplug portion.

From these holes shallow parallel grooves 17 extend along the respectivelongitudinal faces l5, 16 of the plug portion, and terminate at the freeend of the plug portion in slots l8, 19 which extend towards the spineportion and have T-shaped cross-sections. A nose rib 20 extends alongthe length of the plug portion and separates the slots l8, 19 from oneanother.

Carried within the holes 14 in the spine portion ll are phosphor bronzecontact fingers 21 which are located in those holes by anti-withdrawaland location projections 22 and 23 respectively, which projectionsengage in appropriately shaped recesses formed in the outer wall parts24 of the spine portion.

Each contact finger has a hooked end part 25 which engages in, and issecured against movement by, one of the T-shaped slots l8, [9 at thefree end of the plug portion. Sets in each contact finger at 26, 27cause the part of the contact finger lying adjacent the plug por tion ofthe moulding to lie snugly in the appropriate shallow groove 17, and themedian part of the finger to lie adjacent the outer wall part 24 of thespine portion.

Two further sets at 28, 29 in the parts of the contact fingers whichprotrude from the free end of the spine portion cause those parts ofeach pair of contact fingers to converge and to have divergent tip parts30. The spacing of the tip parts from one another is such as to causethem to apply a positive pressure to the appropriate connection pads onthe printed circuit board when the connector is secured thereon.

The connector is assembled simply by inserting the contact fingers 21 inthe holes 14 of the spine portion, and guiding them so that their hookedends 25 enter the appropriate slots 18, 19 on the respective sides ofthe nose rib 20. Each contact finger is finally positioned when theanti-withdrawal and location projections 22, 23 engage in theirrespective recesses.

The sets are then made in the contact fingers at 28 and 29, and theconnection is completed by securing around the ends of the spineportions the clamping bands 13.

To affix the connector to a printed circuit board the connector isplaced with the divergent tip parts of the contact fingers adjacent theedge of the printed circuit board, and pressure is applied to ease thecontact finger tip parts and the clamping bands on to the respectivesurfaces of the board. The connector is secured by bolts passed throughholes in the clamping bands and circuit board, and nuts tightened on thebolts.

The electrical connection of the contact finger tip parts and theconnection pads of the printed circuit board is completed by a solderingprocess.

The plug connector is thereafter ready for use, and has the merit thatit can cooperate with socket connectors which have hitherto been used tomate directly with the edge of the printed circuit board. Furthermore.the plug connector has the merit that it lies in the same general planeas the printed circuit board, and demands no greater separation ofadjacent printed circuit boards than that is required by other pertinentconsiderations.

I claim:

1. An electrical plug connector for a printed circuit board which haselectric circuits and associated edge connection pads on at least oneside of the board comprising an electrical insulating moulding having aspine portion for disposition adjacent an edge of such a printed circuitboard, and a plug portion extending from the spine portion on one sidethereof for disposition remotely from such an edge of a printed circuitboard, and having a transverse thickness substantially equal to that ofthe edge of the printed circuit board, with which it is adapted to beused,

the spine portion having a greater transverse thickness than the plugportion, and two transversely spaced rows of through-holes, which rowsof holes open adjacent the plug portion on opposite sides respectivelyof the plug portion, the holes in each row being spaced apart along thelength of the moulding and the outer wall of each through hole having arecess forming an abutment therein facing away from the plug portionand, t

the plug portion having at its free end two transversely spaced rows ofslots, the slots in each row being positioned along the length of themoulding in alignment with the respective through-holes which open onthe same side of the plug portion, and i a plurality of resilient strip,electrical contact fingers mounted on the plug connector in two parallelrows each comprising a median fastening part, a hooked plug and partextending from the median part at one end thereof, and a printed circuitboard contacting free and part extending from the median part at theopposite end thereof,

each contact finger having its median part extending through and fixedin one of the said through-holes in the moulding adjacent the outer walland having an abutment in detent contact with the abutment in the outerwall and the contact having sets therein, proximate to the plug side ofthe spine portion, to cause the part of the contact finger lyingadjacent the plug portion to lie snugly in the appropriate one ofshallow grooves in the surface of the plug portion, its hooked plug endpart engaged in an associated one of the said slots at the free end ofthe plug portion of the moulding, and its free end part extending fromthe spine portion of the moulding and at least one of the rows ofcontact fingers converging toward the opposite row of contact fingers toprovide a reduced space between them for resiliently receiving betweenthem a printed circuit board having a transverse thickness greater thanthe space between them for guiding a printed circuit board between therows whereby to make electrical connection with an edge connection padof a printed circuit board when the connector is presented to an edgepart thereof,

the said plug portion of the moulding and the contact fingers togethersimulating the edge of such a printed circuit board.

2. An electrical plug connector according to claim 1, wherein the plugportion of the moulding has a longitudinal rib at its free end, whichrib lies between the two rows of slots and projects beyond theextremities of the hooked plug end parts of the contact fingers.

3. An electrical plug connector according to claim 1, wherein the spineportion has longitudinal end extensions which extend beyond the ends ofthe plug portion, and wherein clamping means carried on each said endextension enable the connector to be secured in position on an edge partof a printed circuit board after positioning thereon with the said freeend parts of the contact fingers resting in electrical contact withadjacent edge connection pads formed on the board.

4. An electrical plug connector according to claim 1, wherein eachthrough-hole in the spine portion of the moulding has a T-shapedtransverse cross section having a broad part in which is catried theassociated strip contact finger. and a narrow part extending inwardlyfrom the broad part towards a central part of the spine portion.

5 An electrical plug connector according to claim 4, wherein each slotin the free end of the plug portion of the moulding extends from thesaid free end towards the spine portion, and has a T-shaped transversecrosssection having a broad part in which the hooked plug end of theassociated contact finger is inserted, and a narrow part extendingoutwardly from the broad part towards the contact finger.

6. An electrical plug connector according to claim I, wherein the spineportion has longitudinal end extensions which extend beyond the ends ofthe plug portion, and wherein clamping means carried on each said endextension enable the connector to be secured in position on an edge partof a printed circuit board after positioning thereon with the said freeend parts of the contact fingers resting in electrical contact withadjacent edge connection pads formed on the board.

i. An electrical plug connector according to claim 6, wherein eachthrough-hole in the spine portion of the moulding has a T-shapedtransverse cross section havirig a broad part in which is carried theassociated strip contact finger, and a narrow part extending inwardlyfrom the broad part towards a central part of the spine portion.

8 An electrical plug connector according to claim 7, wherein each slotin the free end of the plug portion of the moulding extends from thesaid free end towards the spine portion. and has a T-shaped transversecrossseetion having a broad part in which the hooked plug end of theassociated contact finger is inserted, and a narrow part extendingoutwardly from the broad part towards the contact finger.

1. An electrical plug connector for a printed circuit board which haselectric circuits and associated edge connection pads on at least oneside of the board comprising an electrical insulating moulding having aspine portion for disposition adjacent an edge of such a printed circuitboard, and a plug portion extending from the spine portion on one sidethereof for disposition remotely from such an edge of a printed circuitboard, and having a transverse thickness suBstantially equal to that ofthe edge of the printed circuit board, with which it is adapted to beused, the spine portion having a greater transverse thickness than theplug portion, and two transversely spaced rows of throughholes, whichrows of holes open adjacent the plug protion on opposite sidesrespectively of the plug portion, the holes in each row being spacedapart along the length of the moulding and the outer wall of eachthrough hole having a recess forming an abutment therein facing awayfrom the plug portion and, the plug portion having at its free end twotransversely spaced rows of slots, the slots in each row beingpositioned along the length of the moulding in alignment with therespective through-holes which open on the same side of the plugportion, and a plurality of resilient strip, electrical contact fingersmounted on the plug connector in two parallel rows each comprising amedian fastening part, a hooked plug and part extending from the medianpart at one end thereof, and a printed circuit board contacting free andpart extending from the median part at the opposite end thereof, eachcontact finger having its median part extending through and fixed in oneof the said through-holes in the moulding adjacent the outer wall andhaving an abutment in detent contact with the abutment in the outer walland the contact having sets therein, proximate to the plug side of thespine portion, to cause the part of the contact finger lying adjacentthe plug portion to lie snugly in the appropriate one of shallow groovesin the surface of the plug portion, its hooked plug end part engaged inan associated one of the said slots at the free end of the plug portionof the moulding, and its free end part extending from the spine portionof the moulding and at least one of the rows of contact fingersconverging toward the opposite row of contact fingers to provide areduced space between them for resiliently receiving between them aprinted circuit board having a transverse thickness greater than thespace between them for guiding a printed circuit board between the rowswhereby to make electrical connection with an edge connection pad of aprinted circuit board when the connector is presented to an edge partthereof, the said plug portion of the moulding and the contact fingerstogether simulating the edge of such a printed circuit board.
 2. Anelectrical plug connector according to claim 1, wherein the plug portionof the moulding has a longitudinal rib at its free end, which rib liesbetween the two rows of slots and projects beyond the extremities of thehooked plug end parts of the contact fingers.
 3. An electrical plugconnector according to claim 1, wherein the spine portion haslongitudinal end extensions which extend beyond the ends of the plugportion, and wherein clamping means carried on each said end extensionenable the connector to be secured in position on an edge part of aprinted circuit board after positioning thereon with the said free endparts of the contact fingers resting in electrical contact with adjacentedge connection pads formed on the board.
 4. An electrical plugconnector according to claim 1, wherein each through-hole in the spineportion of the moulding has a T-shaped transverse cross section having abroad part in which is carried the associated strip contact finger, anda narrow part extending inwardly from the broad part towards a centralpart of the spine portion.
 5. An electrical plug connector according toclaim 4, wherein each slot in the free end of the plug portion of themoulding extends from the said free end towards the spine portion, andhas a T-shaped transverse cross-section having a broad part in which thehooked plug end of the associated contact finger is inserted, and anarrow part extending outwardly from the broad part towards the contactfinger.
 6. An electrical plug connector according to claim 1, whereinthe spine portion has longitudinal end extensions which extEnd beyondthe ends of the plug portion, and wherein clamping means carried on eachsaid end extension enable the connector to be secured in position on anedge part of a printed circuit board after positioning thereon with thesaid free end parts of the contact fingers resting in electrical contactwith adjacent edge connection pads formed on the board.
 7. An electricalplug connector according to claim 6, wherein each through-hole in thespine portion of the moulding has a T-shaped transverse cross sectionhaving a broad part in which is carried the associated strip contactfinger, and a narrow part extending inwardly from the broad part towardsa central part of the spine portion.
 8. An electrical plug connectoraccording to claim 7, wherein each slot in the free end of the plugportion of the moulding extends from the said free end towards the spineportion, and has a T-shaped transverse cross-section having a broad partin which the hooked plug end of the associated contact finger isinserted, and a narrow part extending outwardly from the broad parttowards the contact finger.